Low Rate of AVN and Complications in Unstable SCFE With Epiphyseal-metaphyseal Discontinuity After Treatment With a Modified Dunn Procedure.

BACKGROUND: The risk of developing avascular necrosis (AVN) in the setting of an unstable slipped capital femoral epiphysis (SCFE) that is undergoing treatment with the modified Dunn procedure is not well understood. In addition, since the Loder classification of unstable is reportedly different than actual intraoperatively observed instability (that is, discontinuity between the femoral head epiphysis and proximal femoral metaphysis), the overall risk of developing AVN, as well as the potential complications of treatment of these patients with the modified Dunn procedure, are unknown. QUESTIONS/PURPOSES: To evaluate the modified Dunn procedure for the treatment of patients with epiphyseal-metaphyseal discontinuity, we asked: (1) What was the survivorship free from AVN at 10 years? (2) What was the survivorship free from subsequent surgery and/or complications at 10 years? (3) What were the clinical and patient-reported outcome scores? METHODS: In a retrospective analysis, we identified 159 patients (159 hips) treated with a modified Dunn procedure for SCFE between 1998 and 2020, of whom 97% (155 of 159) had documentation about intraoperatively observed epiphyseal-metaphyseal stability. Of those, 37% (58 of 155) of patients were documented to have intraoperatively observed epiphyseal-metaphyseal discontinuity and were considered eligible for inclusion, whereas 63% (97 of 155) had documented epiphyseal-metaphyseal stability and were excluded. No patients were lost to follow-up before the 2-year minimum. All patients were assessed for survival, but 7% (4 of 58) did not fill out our outcomes score questionnaire. This resulted in 93% (54 of 58) of patients who were available for outcome score assessment. Additionally, 50% (29 of 58) of patients had not been seen within the last 5 years; they are included, but we note that there is uncertainty about their status. The median (range) age at surgery was 13 years (10 to 16), and the sex ratio was 60% (35 of 58) male and 40% (23 of 58) female patients. Sixty-four percent (37 of 58) of patients were classified as acute-on-chronic, and 17% (10 of 58) of patients were classified as acute. Forty-seven percent (27 of 58) of patients presented with severe slips and 43% (25 of 58) of patients with moderate slips based on radiographic classification. All patients underwent surgical hip dislocation with the modified Dunn procedure to correct the slip deformity and provide stabilization. Complications and reoperations were assessed from a review of electronic medical records, and a Kaplan-Meier estimator was used to estimate survivorship free from complications and reoperations at 10 years. Clinical examination results and questionnaire responses were evaluated at minimum 2-year follow-up. RESULTS: Kaplan-Meier survivorship free from AVN was 93% (95% CI 87% to 100%) at 10 years. Survivorship free from any reoperation was 75% (95% CI 64% to 88%) at 10 years. In addition, survivorship free from complications, defined as development of AVN, reoperation, or a Sink Grade II complication or higher, was 57% (95% CI 45% to 73%) at 10 years. The median (range) Merle D'Aubigne Postel score was 18 (14 to 18) for the patients who did not develop AVN, and 12 (6 to 16) for the four patients who developed AVN (p < 0.001). The median modified Harris hip score was 100 (74 to 100) in the non-AVN cohort and 65 (37 to 82) in the AVN cohort (p = 0.001). Median HOOS total score was 95 (50 to 100) in the non-AVN cohort and 53 (40 to 82) in the AVN cohort (p = 0.002). CONCLUSION: Although the modified Dunn procedure is technically challenging, this study shows that in experienced hands, patients with who have demonstrated epiphyseal-metaphyseal discontinuity can be treated with a low risk of AVN and subsequent surgery. Referral of these patients to specialists who have substantial expertise in this procedure is recommended to improve patient outcomes. Prospective, long-term observational studies will help us identify these high-risk patients preoperatively and determine the long-term success of this procedure. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Outcomes of the Modified Dunn Procedure Versus Delayed Imhauser Osteotomy for Moderate to Severe Stable Slipped Capital Femoral Epiphysis.

BACKGROUND: Traditional management of moderate to severe stable slipped capital femoral epiphysis (SCFE) has been in situ fixation followed by reconstructive surgery if symptoms arise. This delayed approach may lead to irreversible intra-articular damage of the hip over time. The purpose of this study was to compare radiographic and clinical outcomes of the modified Dunn procedure (MDP) versus in situ fixation followed by delayed Imhauser osteotomy (DIO). METHODS: This was a retrospective study from a single institution between 2001 and 2021. Among 250 patients diagnosed with SCFE, a total of 18 (18 hips) treated with MDP and 16 (18 hips) treated with DIO for moderate to severe stable SCFE were included. Most patients who underwent DIO either had concomitant (11/18 hips) or subsequent (2/18 hips) open osteochondroplasty. Mean follow up was 4.7 years (range: 1 to 12.8 y). Radiographs were reviewed to measure Southwick angle, anteroposterior and lateral alpha (α) angles, and femoral head-neck offset ratio preoperatively and at latest follow up. Charts were reviewed for demographics, subsequent surgeries, complications, and Heyman-Herndon clinical outcomes. RESULTS: The amount of deformity correction was greater in the MDP than DIO group based on anteroposterior α angles (mean: 22.3 vs. 11.9 degrees, P =0.046) and femoral head-neck offset ratios (mean: 0.26 vs. 0.12, P =0.001). There was no significant difference in Heyman-Herndon scores (both 16/18, 88.9% good to excellent outcomes, P >0.999). Less reoperations were performed in the MDP than DIO group (2/18, 11.1% vs. 9/18, 50%; P =0.004). AVN occurred in 2/18 hips (11.1%) in the MDP group with both surgeries performed early in the series and underwent prior in situ screw fixation compared with 0/18 hips (0%) in the DIO group ( P =0.486). One patient in the DIO group was later diagnosed with osteoarthritis. CONCLUSIONS: MDP resulted in more anatomic coronal and sagittal plane deformity correction, less reoperations, and similar Heyman-Herndon clinical outcomes compared with DIO. AVN occurred in the MDP group whereas osteoarthritis occurred in the DIO group. These complications must be weighed against improved long-term clinical results for patients who would otherwise be at risk for premature degenerative joint disease due to residual proximal femoral deformity. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Pulmonary Embolism in Klippel-Trenaunay-Weber Syndrome With Slipped Capital Femoral Epiphysis.

CASE: A 12-year-old boy with Klippel-Trenaunay-Weber syndrome underwent surgery for unstable slipped capital femoral epiphysis who developed pulmonary embolism postoperatively. CONCLUSION: It is important to be vigilant about pulmonary embolism in children because it is rare but potentially fatal, especially in the presence of risk factors. Early diagnosis and treatment of unstable slipped capital femoral epiphysis are crucial to minimize immobility. Close monitoring of femoral head osteonecrosis is also necessary.

Surgeon Recommendations for Physical Activity in Patients With Pediatric Hip Conditions.

BACKGROUND: While physical activity (PA) is important during youth, it is unclear if children and adolescents with developmental dysplasia of the hip (DDH), Legg-Calvé-Perthes disease (LCPD), or slipped capital femoral epiphysis (SCFE) are expected or encouraged to return to PA once they have healed. This study examines the orthopaedic surgeons' role in advising pediatric hip patients on the PA they should engage in, assessing their practice, opinions, and consensus when making recommendations. METHODS: Orthopaedic surgeons were invited from member lists of 4 hip study groups. The survey included demographics, opinions regarding PA, and 10 case scenarios that queried respondents on the duration and intensity of PA as well as the restrictions on activity type that they would recommend for DDH, LCPD, or SCFE patients. Consensus was evaluated on a scale ranging from 0 to 1, with a value of 0 indicating no agreement among respondents and a value of 1 indicating complete agreement. RESULTS: A total of 51 orthopaedic surgeons responded. While 94% agreed that it is important for school-aged hip patients to return to PA after they have healed, 53% believed that PA may compromise the hip and contribute to the development of osteoarthritis. Average standardized consensus was 0.92 for suggesting the patient engage in some amount of PA, 0.44 for suggesting the recommended daily minimum of 60 minutes of moderate-to-vigorous physical activity (MVPA), and 0.33 for suggesting restrictions on activity type. The most frequently selected restrictions included avoiding impact activities (93%, 235/254) and contact activities (58%, 147/254), followed by weight-bearing activities (24%, 62/254). Respondents were not aware of existing PA guidelines, although 57% expressed interest in following guidelines and 39% were uncertain. CONCLUSIONS: While there is consensus among orthopaedic surgeons that children with chronic hip conditions should engage in PA, there is considerable variation when recommending the recommended daily MVPA minimum and placing restrictions on activity type. This study suggests interest among orthopaedic surgeons in developing PA guidelines that optimize outcomes for pediatric hip patients. LEVEL OF EVIDENCE: Level II-Survey study.

Slipped capital femoral epiphysis after tumor prosthesis implantation in a patient receiving chemotherapy.

While the usual etiology of slipped capital femoral epiphysis (SCFE) is idiopathic, there are many other factors that increase the predisposition to slippage. Chemotherapy can be one of them. In this article, we report a rare case of acute SCFE after tumor prosthesis implantation in a patient who received chemotherapy. A 10-year-old girl with osteosarcoma of the right distal femur underwent (neo-) adjuvant chemotherapy, wide tumor resection, and reconstruction using a growing tumor prosthesis and a short non-cemented femoral stem. Half a year after implantation, she developed aseptic loosening. Revision surgery was performed using a hydroxyapatite (HA)-coated cementless femoral stem. Postoperative plain radiographs revealed SCFE that was treated by closed reduction and screw fixation. The patient recovered without complications, and unaffected hip showed no radiographic signs of slippage on follow-up. The forces of implanting a tumor prosthesis, particularly with a non-cemented stem, can increase the risk of an acute SCFE. The controversy over prophylactic pinning of the uninvolved hip in chemotherapy-associated SCFE is unresolved. Pinning can be considered only in the presence of abnormal prodromal radiological findings.

ChatGPT Responses to Common Questions About Slipped Capital Femoral Epiphysis: A Reliable Resource for Parents?

BACKGROUND: We sought to evaluate the ability of ChatGPT, an AI-powered online chatbot, to answer frequently asked questions (FAQs) regarding slipped capital femoral epiphysis (SCFE). METHODS: Seven FAQs regarding SCFE were presented to ChatGPT. Initial responses were recorded and compared with evidence-based literature and reputable online resources. Responses were subjectively rated as "excellent response requiring no further clarification," "satisfactory response requiring minimal clarification," "satisfactory response requiring moderate clarification," or "unsatisfactory response requiring substantial clarification." RESULTS: ChatGPT was frequently able to provide satisfactory responses that required only minimal clarification. One response received an excellent rating and required no further clarification, while only 1 response from ChatGPT was rated unsatisfactory and required substantial clarification. CONCLUSIONS: ChatGPT is able to frequently provide satisfactory responses to FAQs regarding SCFE while appropriately reiterating the importance of always consulting a medical professional.

Bilateral Slipped Capital Femoral Epiphysis in a Young Girl Treated With Chemotherapy: A Case Report.

CASE: A 1-year-old girl was treated with chemotherapy and hematopoietic stem cell transplantation because of CD40 ligand deficiency. Four years later, she presented with pain in her right leg, diagnosed as atypical acute slipped capital femoral epiphysis, without a clear cause, besides chemotherapy possibly. She was treated with fixation of the epiphysis with a cannulated screw. Two years later, the same diagnosis was made for the left hip and the same surgery was applied. After the 2-year follow-up, clinical outcomes were good. CONCLUSION: Chemotherapy may be a risk factor for atypical slipped capital femoral epiphysis, even without the combination with radiotherapy.

Medium-long-term follow-up of slipped capital femoral epiphysis treated with in situ fixation and patient-acceptable symptom state evaluation.

This study evaluates the Patient Acceptable Symptom State (PASS) in patients with slipped capital femoral epiphysis (SCFE) treated with in situ fixation, focusing on medium to long-term outcomes and quality of life. Its primary goal is to establish a subjective well-being cutoff, using subjective methods and the iHOT33 scale, for assessing patients in future studies. Additionally, it explores functionality differences between mild and moderate-severe SCFE, case series epidemiology and potential complications. A retrospective analysis of 63 patients (73 hips), treated for SCFE between 2000 and 2017 at our facility using in situ fixation, was conducted. These patients underwent clinical, anamnestic, and radiological assessments, with PASS determined based on iHOT33 questionnaire results and statistical analysis. The mean age at surgery was 12.95 years (±1.64, range 9-17), with an average follow-up of 11 years (±4.60, range 5-20). At follow-up, 87% of patients reported achieving PASS, with higher iHOT33 scores correlating to PASS. A cutoff of >68 on the iHOT33 scale showed strong predictive ability for assessing PASS (area under the curve 0.857, 88.89% sensitivity, 79.69% specificity). The findings indicate that 87% of patients achieved PASS at medium to long-term follow-up, with better clinical function than those who did not report PASS. The iHOT33 scale's effectiveness in predicting PASS, especially with a cutoff of >68, suggests this method's efficacy. Given these positive outcomes, including in moderate-severe cases treated with in situ fixation, this approach is considered a viable therapeutic option.

Intraoperative Epiphyseal Perfusion Monitoring Does Not Reliably Predict Osteonecrosis Following Treatment of Unstable SCFE.

BACKGROUND: Avascular necrosis (AVN) remains the most dreaded complication of unstable slipped capital femoral epiphysis (SCFE) treatment. Newer closed reduction techniques (with perfusion monitoring) have emerged as a technically straightforward means to address residual SCFE deformity while still minimizing the risk of osteonecrosis. However, limited data exists regarding the reliability of intraoperative epiphyseal perfusion monitoring to predict the development of AVN. The purpose of this study was to evaluate its reliability. METHODS: We retrospectively reviewed all patients with unstable SCFE who underwent closed or open reduction with epiphyseal perfusion monitoring using an intracranial pressure (ICP) probe from 2015 to 2023 at a single institution with a minimum 6-month radiographic follow-up. Demographic, clinical, and radiographic data were recorded, including duration of symptoms, type of reduction, capsulotomy performed, presence of a waveform on ICP monitoring after epiphyseal fixation, and development of AVN on follow-up radiographs. RESULTS: Our cohort included 33 hips (32 patients), of which 60.6% (n=20) were male. The average age was 12.5±1.8 years, with a median follow-up of 15.8 months. Eleven hips were treated with open reduction using the modified Dunn technique (10 hips) or anterior approach (1 hip), and 22 hips were treated with inadvertent (5 hips) or purposeful closed reduction using the Leadbetter technique (17 hips). Overall, 8 of the 33 hips in our series (24.2%) developed AVN, 6 of which (20%) had a pulsatile waveform on intraoperative epiphyseal perfusion monitoring. The overall rate of AVN after closed reductions was 31.8% (7 of 22 hips); the incidence of AVN after closed reduction with a detectable waveform was 30% (6 of 20 hips). There was no significant association between time to surgery ( P =0.416) or type of reduction ( P =0.218) and the incidence of AVN. CONCLUSIONS: In this series, intraoperative epiphyseal perfusion monitoring did not reliably predict the development of osteonecrosis. To our knowledge, this is the first study to report AVN after demonstrable intraoperative epiphyseal perfusion following closed reduction of unstable slips. LEVEL OF EVIDENCE: Level IV: case series-therapeutic study.

Limited angular remodelling after in-situ fixation for slipped capital femoral epiphysis : A study on radiographs from the Swedish pediatric orthopaedic quality registry for SCFE.

BACKGROUND: In Sweden, most children with slipped capital femoral epiphysis (SCFE) are operated on with a single smooth pin or a short-threaded screw, allowing further growth of the femoral neck. Using the Swedish Pediatric Orthopaedic Quality registry, SPOQ, we investigated whether angular remodelling occurs adjacent to the proximal femoral epiphysis after fixation of SCFE using implants, allowing continued growth of the femoral neck. METHODS: During 2008-2010 a total national population of 155 children were reported to the SPOQ registry. Following our strict inclusion criteria, radiographs of 51 hips were further assessed. The lateral Head Shaft Angle (HSA), the Nötzli 3-point α-angle, the anatomic α-angle, and the Anterior Offset Ratio (AOR) on the first postoperative radiographs and at follow-up were measured to describe the occurrence of remodelling. Slip severity was categorised as mild, moderate or severe according to postoperative HSA. RESULTS: Mean and SD values for the change in HSA were 3,7° (5,0°), for 3-point α-angle 6,8° (8,9°), and anatomic α-angle 13,0° (16,3°). The overall increase in AOR was 0,038 (0.069). There were no significant differences between the slip severity groups. CONCLUSIONS: We found limited angular remodelling after in situ fixation with smooth pins or short threaded screws for SCFE. The angular remodelling and the reduction of the CAM deformity was less than previously described after fixation of SCFE with similar implants. Results about the same magnitude with non-growth sparing techniques suggest that factors other than longitudinal growth of the femoral neck are important for angular remodelling.

Rate and Risk Factors for Contralateral Slippage in Adolescents Treated for Slipped Capital Femoral Epiphysis: A Comprehensive Analysis of 3,528 Cases.

BACKGROUND: After a unilateral slipped capital femoral epiphysis (SCFE), the contralateral hip is at risk for a subsequent SCFE. However, further information with regard to risk factors involved in the development of contralateral SCFE must be investigated. The purpose of this study was to report the rate and risk factors for subsequent contralateral SCFE in adolescents treated for unilateral SCFE by exploring a mix of known and potential risk factors. METHODS: A case-control study utilizing aggregated multi-institutional electronic medical record data between January 2003 and March 2023 was conducted. Patients <18 years of age diagnosed with SCFE who underwent surgical management were included. Variables associated with contralateral SCFE were identified using multivariable logistic regression models that adjusted for patient characteristics and time of the surgical procedure, providing adjusted odds ratios (ORs). The false discovery rate was accounted for via the Benjamini-Hochberg method. RESULTS: In this study, 15.3% of patients developed contralateral SCFE at a mean (and standard error) of 296.53 ± 17.23 days and a median of 190 days following the initial SCFE. Increased thyrotropin (OR, 1.43 [95% confidence interval (CI), 1.04 to 1.97]; p = 0.022), diabetes mellitus (OR, 1.67 [95% CI, 1.22 to 2.49]; p = 0.005), severe obesity (OR, 1.81 [95% CI, 1.56 to 2.57]; p < 0.001), history of human growth hormone use (OR, 1.85 [95% CI, 1.10 to 3.38]; p = 0.032), low vitamin D (OR, 5.75 [95% CI, 2.23 to 13.83]; p < 0.001), younger age in boys (under 12 years of age: OR, 1.85 [95% CI, 1.37 to 2.43]; p < 0.001) and in girls (under 11 years of age: OR, 1.47 [95% CI, 1.05 to 2.02]; p = 0.026), and tobacco exposure (OR, 2.43 [95% CI, 1.49 to 3.87]; p < 0.001) were significantly associated with increased odds of developing contralateral SCFE. CONCLUSIONS: In the largest study on this topic, we identified the rate, odds, and risk factors associated with development of contralateral SCFE. We found younger age, hypothyroidism, severe obesity, low vitamin D, diabetes mellitus, and a history of human growth hormone use to be independent risk factors. Our findings can aid clinical decision-making in at-risk patients. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Is Subcapital Realignment for Slipped Capital Femoral Epiphysis a Reproducible Technique? Midterm Results.

BACKGROUND: The modified Dunn procedure, which is based on the development of an extended retinacular flap containing the blood supply for the femoral head, allows anatomic reestablishment in patients with moderate to severe slipped capital femoral epiphysis (SCFE). Some controversy exists regarding the short-term to midterm risk of avascular necrosis (AVN) and other complications resulting from the surgical technique. QUESTIONS/PURPOSES: (1) What percentage of patients treated with an extended retinacular flap during the modified Dunn procedure for SCFE with a moderate (slip angle from 30° to 60°) or severe slip (slip angle equal or greater than 60°) develop symptomatic AVN, and what percentage underwent further surgery or had other complications? (2) What femoral head-neck alignment and position parameters relative to the greater trochanter are achieved after surgery? (3) Can we identify radiographic signs of osteoarthritis at a minimum of 4 years after surgery? METHODS: Between January 2006 and December 2018, we treated 61 patients for SCFE. During this time, we generally used the modified Dunn procedure when the slip angle was ≥ 30°. Based on this indication, the modified Dunn procedure was performed in 37 patients (41 hips) during that time period, and those patients were potentially eligible for this retrospective study. Because bilateral hips in the same patient are not statistically independent, for our analyses, we analyzed only the hip with the longer follow-up time. Of those who remained, 11% (4) were lost before the minimum study follow-up of 48 months or had incomplete datasets, leaving 89% (33) for analysis here at a median follow-up of 80 months (range 49 to 208 months). Periacetabular osteotomy or subtrochanteric rotational femoral osteotomy was added under the same anaesthesia time in 33% (11 patients). We added periacetabular osteotomy in 24% (8) when intraoperative anterior instability was present in external rotation. A femoral rotational osteotomy was added in 9% (3) when posterior instability was present in flexion and internal rotation. The mean ± standard deviation age at the time of surgery was 13 ± 1 years, and 33% (11 of 33) of patients were female. The mean slip angle was 51° ± 16º, and 15% (5) of hips had unstable slips, defined as an inability to walk with or without crutches. We documented chronic presentations in 82% (27) of patients, acute and chronic in 12% (4), and acute in 6% (2). The rate of symptomatic AVN was determined by reviewing all radiographs obtained at the latest follow-up interval. Further surgery and other complications were assessed through an electronic medical record review. Radiographic morphologic parameters were measured before surgery and at a minimum follow-up of 4 years by two senior orthopaedic surgeons. Radiographs obtained at the latest follow-up visit were also screened for signs of osteoarthritis by the same surgeons. RESULTS: At the latest follow-up, 3% (1 patient) of patients developed symptomatic AVN and underwent further surgery and 3% (1) underwent revision surgery for screw breakage after a high-energy fall. Postoperatively, the alpha angle was restored to 39º ± 6º, the anterior head-neck offset was restored to 8 ± 3 mm, the neck-shaft angle was 136º ± 6º, and the presence of a positive Klein line decreased from 64% (21 hips) to 0% (0 hips). No patients showed radiographic signs of osteoarthritis at the minimum follow-up of 4 years. CONCLUSION: In this series, the modified Dunn procedure in moderate and severe slips was a reproducible procedure, and few patients developed symptomatic AVN or experienced other complications. Hip morphology was restored, but a longer follow-up duration and a detailed analysis of the results from other centers is warranted to assess the possible long-term risk of progression to AVN or osteoarthritis. LEVEL OF EVIDENCE: Level IV, therapeutic study.